Striking Stability of a Substituted Silicon(II) Bis(trimethylsilyl)amide and the Facile Si–Me Bond Cleavage without a Transition Metal Catalyst

Silicon(II) bis(trimethylsilyl)amide (LSiN(SiMe3)2, L= PhC(NtBu)2) (2) has been synthesized by the reaction of LSiHCl2 with KN(SiMe3)2 in 1:2 molar ratio in high yield where 1 equiv of the latter functions as a dehydrochlorinating agent. 2 exhibits a high stability up to 154 °C and can be handled in open air for a short period of time without any appreciable decomposition. An amazing five-membered cyclic silene (3) results from the cleavage of one Si–Me bond of 2 with an adamantyl phosphaalkyne. 3 is the first example of a heavy cyclopentene derivative which consists of four different elements, C, N, Si, and P. Both compounds are characterized by multinuclear NMR spectroscopy, EI-mass spectrometry, and single crystal X-ray diffraction studies.